JP2009244791A - Negative type photosensitive green composition, negative type green film for green filter, negative type photosensitive blue composition, negative type blue film for blue filter, negative type photosensitive red composition, negative type red film for red filter, color filter and method of manufacturing color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide negative type photosensitive green, blue and red colored compositions, negative type photosensitive green, blue and red colored films for a filter, a color filter and a method of manufacturing a color filter, which achieve precise formation of a filter having a small-size shape. <P>SOLUTION: In the green, blue or red composition, a ratio (I/M) of monomer (M) to initiator (I) is 20 to 40% and each of monomer species and polymer species has a single composition. Further, a sum quantity of the initiator and monomer per the total resin quantity is 4 to 6% in the green composition, is 6 to 7% in the blue composition and is 3.5 to 6% in the red composition. The method of manufacturing the color filter includes processes of: forming the negative type films 18 by using green, blue and red colored compositions in accordance with a plurality of photo-electric conversion elements 12 in an imaging device 14; performing pattern-exposure of the films via a density distribution mask; and thereafter, developing the film to form the outer surface of each color filter into a convex lens shape. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a negative photosensitive green composition, a negative green film for a green filter, a negative photosensitive blue composition, a negative blue film for a blue filter, a negative photosensitive red composition, and a negative red for a red filter. It relates to membranes, color filters, and methods of manufacturing color filters.

  Negative photosensitive green composition, negative photosensitive blue composition, and negative photosensitive green film, negative photosensitive blue film, and negative photosensitive red film made from negative photosensitive red composition It has been conventional to use optical filters having a desired light transmittance, such as green filters, blue filters, and red filters.

  A color image sensor provided with these filters is also conventionally known.

  In a conventional color image sensor, filters of a plurality of colors (in this case, filter segments) are formed on a plurality of photoelectric conversion elements provided on a semiconductor substrate by using a photolithography technique so as to be adjacent to each other without a gap. A set of multiple color filter segments constitutes a color filter. Each filter segment has a thickness of several μm.

  In recent years, the number of pixels of an image sensor has been increased, and in recent years, the number of pixels has reached several million. In addition, as the number of pixels increases, the ratio of the area occupied by various wirings and electronic circuits for operating each pixel in each pixel increases. As a result, the ratio of the area (aperture ratio) that can be used for the actual light reception of the photoelectric conversion element in each pixel is about 20 to 40%. This means that the photosensitivity of the image sensor is lowered.

  In order to improve the photosensitivity of the image sensor 50, a micro lens 56 is disposed on the filter segments 52a, 52b, 52c of the color filter 52 corresponding to the photoelectric conversion element 54 as shown in FIG. JP-A-59-122193 (Patent Document 1), JP-A-60-38989 (Patent Document 2), JP-A-60-53073 (Patent Document 3), and JP-A-2005-294467. No. 4 (Patent Document 4).

Further, as shown in FIG. 11B, it is disclosed in Japanese Patent Laid-Open No. 59-198754 (Patent Document 5) that hemispherically colored microlenses 58a, 58b, and 58c are used as color filter segments. ing.
JP 59-122193 A JP 60-38989 A JP 60-53073 A JP 2005-294467 A JP 59-198754 A

  However, in the structure of the conventional color image sensor shown in FIG. 11A, the color LB is mixed with the light LB in the vicinity of the side surfaces adjacent to each other of the color filter segments 52a, 52b, and 52c without any gap. Is likely to occur.

  That is, a part of the light beam LB incident from an oblique direction on the side surface portions of the color filter segments 52a, 52b, 52c close to the micro lens 56 includes the side surface portions of the color filter segments 52a, 52b, 52c. And enters the adjacent color filter segments 52a, 52b, 52c, and causes color mixing in the light near the side surfaces of the adjacent color filter segments 52a, 52b, 52c. In the photoelectric conversion element 54 in which the color mixture has occurred, the color reproducibility and the lightness are lowered, and the entire image pickup element 50 causes color unevenness.

  Further, in the conventional example in which hemispherically colored macro lenses 58a, 58b, and 58c are used as color filter segments as shown in FIG. 11B, the central portion and the peripheral portion of the macro lenses 58a, 58b, and 58c There are differences in the lengths of the optical paths LC and LP of light passing through the macro lenses 58a, 58b, and 58c after entering the macro lenses 58a, 58b, and 58c. If there is a difference in the length of the optical path passing through the color filter segment, a difference occurs in the coloring of the light beam passing through each optical path. In the macro lenses 58a, 58b, and 58c, the amount of light that passes through the peripheral portion is larger than the amount of light that passes through the central portion. As a whole, the color becomes light and a color image pickup device with low color separation ability is obtained.

  In order to solve the disadvantages of the conventional color image sensor, the present inventors have proposed the following technologies in Japanese Patent Application Nos. 2006-102121 and 2006-115901.

  That is, as shown in FIG. 12, the color which has the color filter segment 60a, 60b, 60c with a micro lens made into the shape which laminated | stacked the micro lens integrally on the color filter segment which has a side surface with the photosensitive coloring composition. It is an image sensor.

  In addition, the inventors propose to use a photolithographic method using a halftone mask having gradation as a mask for pattern exposure to form the color filter segments 60a, 60b, 60c with microlenses having such a structure. is doing.

  For example, it has an opening forming portion that is a large circular transmission portion around the center of the photoelectric conversion element, and a gradation changing portion that sequentially changes the gradation (grayscale) in a plurality of concentric circles with respect to the opening forming portion. A mask is used.

  When the halftone mask having gradation is irradiated with light, the amount of light passing through the mask changes in accordance with each gradation formed on the mask. Therefore, if pattern development is performed on a photosensitive composition through a halftone mask having gradation, development is performed, and a photosensitive film having a portion having a thickness that varies depending on a change in the amount of light exposed to the photosensitive composition. An ionic composition is obtained.

  Therefore, it has an opening forming portion that is a large circular transmission portion around the center of the photoelectric conversion element, and a gradation changing portion that sequentially changes the gradation (grayscale) in a plurality of concentric circles with respect to the opening forming portion. If pattern exposure and development are performed on the photosensitive composition using a mask, a color filter having a hemispherical lens portion having a convex cross section laminated thereon can be obtained.

  However, in the conventional photosensitive coloring composition, the shape and dimensions of the formed product obtained after pattern exposure through a halftone mask and development are precisely controlled according to the gradation of the halftone mask. It was not obtained. For this reason, there is a problem that the curvature of a portion to be a microlens is not desired and satisfactory light condensing performance cannot be obtained. There is also a photosensitive coloring composition having such a composition that the shape obtained after pattern exposure through a halftone mask and development can be obtained according to the gradation of the halftone mask. There is also a problem in that the color filter formed with such a photosensitive coloring composition and the adhesion between the substrate and the base are deteriorated, and a color filter having a fine pattern cannot be obtained.

  That is, in the conventional photosensitive coloring composition, the shape of the formed product obtained after pattern exposure through a halftone mask and development is good, the surface is smooth, the resolution and adhesion are good, and the residue There was no photosensitive coloring composition without any.

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide a negative photosensitive green composition capable of precisely controlling and forming a filter having a desired size and shape even when the size of the filter is smaller. , Negative green film for green color filter, negative photosensitive blue composition, negative blue film for blue color filter, negative photosensitive red composition, negative red film for red color filter, color filter, and color filter It is to provide a manufacturing method.

  In order to achieve the above-mentioned object of the present invention, the negative photosensitive green composition according to the present invention is: a negative photosensitive composition in which at least a solvent, a green pigment, a monomer, a polymer, an initiator, and an additive are mixed. The ratio of the initiator (I) to the monomer (M) (I / M) is in the range of 20% to 40%, and the initiator (I), the monomer (M) and the polymer (P The total amount of the initiator (I) and the monomer (M) with respect to the total resin amount (SP) is in the range of 4% to 6%, and the monomer species has a single composition and the polymer species is single. It is characterized by having one composition.

  In order to achieve the above-described object of the present invention, a negative green film for a green color filter according to the present invention is a negative green film for a green filter having a film thickness in the range of 0.5 to 2.5 μm. And has a substantially convex spectral transmittance curve in the wavelength region of visible light, and the transmittance of light having wavelengths between 400 nm and 435 nm and between 620 nm and 660 nm is 10% or less, and 480 nm Between 515 nm and between 560 nm and 600 nm, there is a wavelength at which the light transmittance is 50%, and the light transmittance at a wavelength of 530 nm is 70% or more.

  In order to achieve the above-mentioned object of the present invention, another negative green film for green color filter according to the present invention is: negative green for green filter having a film thickness in the range of 0.5 to 2.5 μm. The film has a substantially convex spectral transmittance curve in the visible light wavelength region, and has a light transmittance of 10% or less between 400 nm and 435 nm and between 620 nm and 660 nm. Between 460 nm and 510 nm and between 550 nm and 600 nm, the light transmittance is 50%, and the light transmittance at 530 nm wavelength is 70% or more. Yes.

  In order to achieve the above-mentioned object of the present invention, the negative photosensitive blue composition according to the present invention comprises: a negative photosensitive composition in which at least a solvent, a blue pigment, a monomer, a polymer, an initiator, and an additive are mixed. The composition (I / M) of the initiator (I) to the monomer (M) is in the range of 20% to 40%, and the initiator (I), the monomer (M) and the polymer (P The total amount of the initiator (I) and the monomer (M) with respect to the total resin amount (SP) is in the range of 6% to 7%, and the monomer species has a single composition and the polymer species is also single. It is characterized by having one composition.

  In order to achieve the above-mentioned object of the present invention, the negative blue film for a blue color filter according to the present invention is a negative blue film for a blue filter having a film thickness in the range of 0.5 to 2.5 μm. In the visible light wavelength region, it has a substantially convex spectral transmittance curve, the transmittance of light of 400 nm wavelength is 40% or more, and the transmittance of light between 480 nm and 520 nm is 50%. And the transmittance of light having a wavelength of 700 nm is 20% or less.

  In order to achieve the object of the present invention described above, the negative photosensitive red composition according to the present invention is: a negative photosensitive composition in which at least a solvent, a red pigment, a monomer, a polymer, an initiator, and an additive are mixed. The composition (P) has a ratio (I / M) of the initiator (I) to the monomer (M) in the range of 20% to 40%, and the initiator (I), the monomer (M) and the polymer (P And the total amount of initiator (I) and monomer (M) with respect to the total resin amount (SP) in the range of 3.5% to 6%, and the monomer species is a single composition and the polymer species Is also characterized by a single composition.

  In order to achieve the object of the present invention described above, the negative red film for red color filter according to the present invention is a negative red film for red filter having a film thickness in the range of 0.5 to 2.5 μm. Thus, it has a substantially S-shaped spectral transmittance curve in the wavelength region of visible light, the transmittance of light with a wavelength of 400 nm is 20% or less, and the transmittance of light with a wavelength between 430 nm and 560 nm is 10%. %, Having a wavelength at which the light transmittance is 50% between 570 nm and 600 nm, and the light transmittance at 600 nm wavelength is 75% or more.

  In order to achieve the above-mentioned object of the present invention, one color filter according to the present invention is: a color filter comprising at least one green filter segment arranged corresponding to a plurality of photoelectric conversion elements of an image sensor. The green filter segment is formed of the negative photosensitive green composition according to the present invention described above, and the green filter segment contains 20 to 55% by weight of a green pigment. It is characterized by that.

  In order to achieve the above-mentioned object of the present invention, another color filter according to the present invention is: a color filter comprising at least one blue filter segment arranged corresponding to a plurality of photoelectric conversion elements of an image sensor. The blue filter segment is formed of the negative photosensitive blue composition according to the present invention described above, and the blue filter segment contains 15 to 45% by weight of a blue pigment. It is characterized by that.

  In order to achieve the above-mentioned object of the present invention, still another color filter according to the present invention is: a color comprising at least one red filter segment arranged corresponding to a plurality of photoelectric conversion elements of an image sensor. The red filter segment is formed of the negative photosensitive red composition according to the present invention described above, and the red filter segment contains 20 to 50% by weight of a red pigment. It is characterized by that.

  In order to achieve the object of the present invention described above, one color filter manufacturing method according to the present invention is: a negative according to the present invention described above corresponding to at least one of a plurality of photoelectric conversion elements of an image sensor. A negative green film is formed from the photosensitive green composition, developed after pattern exposure of the negative green film using a density distribution mask, and the surface located on the opposite side of the corresponding photoelectric conversion element after development is A green filter having a convex lens shape is formed.

  In order to achieve the above-described object of the present invention, another color filter manufacturing method according to the present invention is in accordance with the present invention described above corresponding to at least one of a plurality of photoelectric conversion elements of an image sensor. A negative blue film is formed from a negative photosensitive blue composition, the negative blue film is developed after pattern exposure using a density distribution mask, and the surface located on the opposite side of the corresponding photoelectric conversion element after development A blue filter having a convex lens shape is formed.

  In order to achieve the above-described object of the present invention, another color filter manufacturing method according to the present invention is as follows: According to the present invention described above corresponding to at least one of a plurality of photoelectric conversion elements of an image sensor. A negative red film is formed from the negative photosensitive red composition, and the negative red film is developed after pattern exposure using a density distribution mask, and is located on the side opposite to the corresponding photoelectric conversion element after development. A red filter whose surface is formed in a convex lens shape is formed.

  Negative photosensitive green composition, negative green film for green color filter, negative photosensitive blue composition, negative blue film for blue color filter according to the present invention, characterized in that it is configured as described above , Negative photosensitive red composition, negative red film for red color filter, color filter, and color filter manufacturing method, even if the size of the color filter is smaller, the color filter of the desired size and shape is precisely Allows to form in control.

  From FIG. 1 to FIG. 4, the color filter is manufactured by the color filter manufacturing method according to the embodiment of the present invention corresponding to at least one photoelectric conversion element with respect to an imaging element including a plurality of photoelectric conversion elements. A state of manufacturing will be described.

  FIG. 1 shows a schematic longitudinal section of an image sensor 14 in which a plurality of CMOS photoelectric conversion elements 12 are provided on a semiconductor substrate 10. In this embodiment, the photoelectric conversion element 12 is a CMOS photoelectric conversion element. However, according to the concept of the present invention, the photoelectric conversion element 12 may be a CCD photoelectric conversion element. Such a configuration of the image sensor 14 is well known and will not be described in further detail here.

  The pixel size in plan view to which the present invention can be applied is in the range of about 10 μm to about 1 μm, and in this embodiment, it is in the range of about 2.5 μm to about 2.2 μm.

  In order to use the image pickup device 14 as a color image pickup device, the plurality of photoelectric conversion elements 12 of the image pickup device 14 are covered with a filter of green, blue, or red (hereinafter referred to as a filter segment) in a predetermined arrangement. In other words, the light transmitted through each filter must be received, and a set of filter segments of a plurality of colors is called a color filter.

  For the plurality of photoelectric conversion elements 12 of the image sensor 14, normally, a green filter segment is first formed in a predetermined arrangement. Next, a blue filter segment or a red filter segment is formed in a predetermined arrangement, and finally, the remaining color filter segments are formed in a predetermined arrangement, so that the plurality of photoelectric conversion elements 12 are green, blue in a predetermined arrangement. , And covered by filter segments of either red color.

  When the plurality of photoelectric conversion elements 12 of the image sensor 14 are covered with a filter segment of any one of green, blue, and red in a predetermined arrangement, as shown in FIG. 2, the semiconductor of the image sensor 14 It is preferable to form an ultraviolet absorbing layer 16 on the surface of the substrate 10 facing the plurality of photoelectric conversion elements 12 and further form a negative color resist layer 18 of a desired color thereon.

  In this embodiment, the thickness UVH of the ultraviolet absorbing layer 16 is between about 0.1 μm and about 0.8 μm. However, if the ultraviolet rays do not adversely affect the plurality of photoelectric conversion elements 12, they absorb ultraviolet rays. Layer 16 can also be omitted.

[Formation of green filter segment]
First, when the green filter segment is formed on the predetermined corresponding photoelectric conversion element 12, the negative color resist layer 18 is constituted by the negative green film formed of the negative photosensitive green composition, In this case, the thickness RH of the negative color resist layer 18 is set in the range of 0.5 μm to 2.5 μm.

  The negative photosensitive green composition is a negative photosensitive green composition in which at least a solvent, a green pigment, a monomer, a polymer, an initiator, and an additive are mixed, and is an initiator (I) for the monomer (M). ) Ratio (I / M) is in the range of 20% to 40%, and the initiator (I) and the monomer with respect to the total resin amount (SP) of the initiator (I), the monomer (M) and the polymer (P) The total amount with (M) ranges from 4% to 6%, and the monomer species is a single composition and the polymer species is also a single composition.

  The monomer (M) is a trifunctional acrylic monomer. The polymer has an acid value in the range of 60-100 and an average molecular weight of 10,000-50,000.

  The green pigment is C.I. I. Pigment green 36, C.I. I. Pigment Green 7 and C.I. I. Pigment Yellow 139 or C.I. I. Pigment green 36 and C.I. I. Pigment Yellow 150 is included.

  In any case, the concentration of the green pigment in the green filter segment is adjusted to be in the range of 20 to 55% by weight.

More details:
Examples of the solvent include cyclohexane, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl n-amyl ketone, propylene glycol monomethyl ether toluene, methyl ethyl ketone, Ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, and other petroleum solvents can be used alone or in combination.

  Examples of monomers include pentaerythritol tri and tetraacrylate, trimethylolpropane triacrylate, trimethylolpropane PO modified (n = 1) triacrylate, trimethylolpropane PO modified (n = 2) triacrylate, trimethylolpropane EO modified ( n = 1) triacrylate, trimethylolpropane EO modified (n = 2) triacrylate, dipentaerythritol penta and hexaacrylate, pentaerythritol tetraacrylate, ditrimethylolpropane tetraacrylate, isocyanuric acid EO modified di and triacrylate, isocyanuric Acid EO-modified citriacrylate or the like can be used.

  Examples of the polymer include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, Thermoplastic resins such as polyester resins, acrylic resins, alkyd resins, polystyrene resins, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polyethylene (HDPE, LDPE), polybutadiene, polyimide resins, and epoxy resins, for example Thermosetting resins such as benzoguanamine resin, rosin-modified maleic acid resin, rosin-modified fumaric acid resin, melanin resin, urea resin, and phenol resin can be used.

  The polymer contains an active energy ray curable resin. As the active energy ray-curable resin, for example, a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group or an amino group has a reactive substituent such as an isocyanate group, an aldehyde group or an epoxy group (meta ) Resins in which photocrosslinkable groups such as (meth) acryloyl groups and stil groups are introduced into the linear polymer by reacting acrylic compounds and cinnamic acid, styrene / maleic anhydride copolymers, α-olefins / anhydrides A product obtained by half-esterifying a linear polymer containing an acid anhydride such as a maleic acid copolymer with a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate can be used.

  Further, the initiator contains a photopolymerizable initiator. Examples of the photopolymerizable initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy) -2-methylpropan-1-one. , 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2- Acetophenone photopolymerization initiators such as morpholinopropan-1-one, benzoin photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, Benzoyl repose Benzophenone photopolymerization initiators such as methyl acid, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4-methyldiphenyl sulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropyl Thioxanthone photopolymerization initiators such as thioxanthone and 2,4-diisopropylthioxanthone, 2,4,6-trichloro-S-triazine, 2-phenyl-4,6-bis (trichloromethyl) -S- Triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloromethyl) -S-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -S-triazine, 2-piperonyl -4,6-bis (trichloromethyl) -S-triazine, 2 4-Bis (trichloromethyl) -6-styryl-S-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -S-triazine, 2- (4-methoxy-naphth-1) -Yl) -4,6-bis (trichloromethyl) -S-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl (4-methoxystyryl) -6-triazine, etc. These triazine photopolymerization initiators, borate photopolymerization initiators, carbazole photopolymerization initiators, imidazole photopolymerization initiators, and the like can be used.

  The surface of the negative type color resist layer 18 formed of the negative type green film is formed by using a halftone mask 20 with a plurality of portions corresponding to the plurality of photoelectric conversion elements 12 to be formed corresponding to the green filter segments. Pattern exposure 22 is performed. The halftone mask 20 is a hemisphere having a convex cross section centered on the center of the photoelectric conversion element 12 corresponding to each of the plurality of portions exposed by the halftone mask 20 in the green negative color resist layer 18 after development. It has the gradation of the pattern that has a shape.

FIG. 3 shows a schematic plan view of the halftone mask 20 to be used. Normally, the halftone mask has a size 4 to 5 times the size of the pattern to be actually formed, and pattern exposure is performed by reducing the size to 1/4 to 1/5 during pattern exposure. The halftone mask changes the gradation (gray scale) in a concentric manner. The gradation can be changed by adjusting the number of fine black dots (or white dots) per unit area on the halftone mask, for example, when the reduction is 1/5, for example, with a size smaller than the wavelength of the exposure light. I can do it. As a result, the halftone mask can have a gradation in which the light transmittance changes concentrically.
In the halftone mask 20 used in this embodiment, the number of black dots that block light is reduced toward the center in a plurality of concentric circles centered on the center of the photoelectric conversion element 12, and as a result, the center approaches the center. The light transmittance increases concentrically.

  The halftone mask 20 of this embodiment is a 4 to 5 times reticle, and has a pattern with a size 4 to 5 times larger than the size of the pattern exposed on the surface of the negative color resist layer 18. Yes. A stepper exposure apparatus (not shown) is used to reduce the pattern of the halftone mask 20 to 1/4 to 1/5 and expose the surface of the negative color resist layer 18.

  Thereafter, the negative color resist layer 18 is developed. By performing pattern exposure through a halftone mask, the exposure amount irradiated to the resist layer portion changes, so the film thickness of the resist layer remaining after development changes according to the exposure amount. Therefore, only the plurality of portions exposed in the negative color resist layer 18, that is, the plurality of portions positioned on the side opposite to the plurality of photoelectric conversion elements 12 for which green filter segments are to be formed correspondingly, are illustrated in FIG. 4, a green filter segment 24 having a hemispherical outer surface 24a having a convex cross section centered on the center of the corresponding photoelectric conversion element 12 is left as shown in FIG.

  At this time, in this embodiment, the side surface 24b rising substantially vertically from the ultraviolet absorbing layer 16 in the filter segment 24 has a height BH of approximately 0.7 μm from the ultraviolet absorbing layer 16 to the edge opposite to the ultraviolet absorbing layer 16. Moreover, the convex hemispherical outer surface 24a on the upper part of the filter segment 24 has a height PH of approximately 0.5 μm from the edge to the apex of the side surface 24b.

  Finally, the filter segment 24 thus formed is hardened.

The inventor of the present application: variously changed the ratio (I / M) of the initiator (I) to the monomer (M) within a range of 20% to 40%, and the initiator (I) and the monomer (M) The total amount (IM amount) of the initiator (I) and the monomer (M) with respect to the total resin amount (SP) with the polymer (P) is variously changed within a range of 4% to 6%, and further the green filter segment 10 types (Examples 1 to 10) of negative photosensitive green compositions having the same composition were prepared, except that the concentration (Pcon) of the green pigment was varied in the range of 20 to 55% by weight. Ten types (Examples 1 to 10) of green (Examples 1 to 10) prepared according to the color filter manufacturing method described above with reference to FIGS. Cross-sectional shape for each filter segment Surface roughness, resolution, adhesion, and evaluated for residue. In addition, at least one of the ratio (I / M), the total amount (IM amount), and the concentration (Pcon) is deviated from the above range, or two polymer types are used. 14 types of negative photosensitive green compositions having the same composition (Comparative Examples 1 to 14) were prepared, and using these 14 types of negative photosensitive green compositions (Comparative Examples 1 to 14), FIGS. The cross-sectional shape, surface roughness, resolution, adhesion, and residue were evaluated for each of the 14 types (Comparative Examples 1 to 14) of green filter segments prepared according to the color filter manufacturing method described above with reference to FIG. I did it. The results are summarized in Table 1 below.

  Here, the cross-sectional shape was judged using an AFM (atomic force microscope). In other words, the curved shapes of the cross section orthogonal to the two sides passing through the center of the green filter segment 24 having a substantially square shape and opposite to each other and the cross section along the diagonal line should be obtained from the used halftone mask. It was judged by the situation of separation from the ideal curve shape for condensing light. FIGS. 5A and 5B show examples of cases where these cross-sectional shapes are allowed close to the desired curve shape (OK) and cases where the cross-sectional shape is not allowed to deviate from the desired curve shape (NG). Has been.

  The surface roughness was measured using an SEM (operational electron microscope) and judged by comparison with a predetermined limit sample. FIGS. 6A, 6B, and 6C each show an example (NG) that is outside the allowable range, a limit sample, and an example that is within the allowable range (OK).

  The resist pattern resolution (determining whether the pattern dimension obtained by pattern exposure and development is the desired dimension) is determined using a side length SEM (side length / operation type electron microscope). Measured and judged. The judgment criteria were “◯” if the pattern size was in the range of 2 μm ± 0.1 μm, and “x” and “Δ” if the pattern size was off.

Further, the adhesion was confirmed using a microscope, and the determination criterion was determined by whether or not peeling occurred when exposed and developed with a certain amount of light or more. In addition to Table 1, the determination of exposure amount and adhesiveness is additionally described in Table 2 below.

  Moreover, the residue was observed using a side length SEM (side length / operation type electron microscope), and judged by comparison with a predetermined limit sample. FIGS. 7A, 7B, and 7C show an example of a non-permissible range (NG), an example of a permissible range (OK), and a limit sample, respectively.

  In any case, if the cross-sectional shape, surface roughness, resolution, adhesion, and residue are not within the criteria and tolerances as described above, the green filter segment as described above will exhibit practically desirable performance. I know I can't.

  That is, if the cross-sectional shape is poor, the desired curvature cannot be obtained and the light collecting property is deteriorated. If the surface roughness is rough, light is scattered on the lens surface, which causes color mixing and noise due to the scattered light. If the resolution is poor, a fine pattern cannot be obtained, and if there is a large amount of residue remaining in the unexposed area after development, color mixing and noise are caused.

  And the following was found in the process of analyzing Table 1 and in the process of creating Examples 1-10 and Comparative Examples 1-14 and evaluating performance.

  -In the negative photosensitive green composition, if the ratio (I / M) of the initiator (I) to the monomer (M) is 20% to 40%, a negative color resist formed by a negative green film The outer surface obtained by developing after pattern exposure in the layer 18 through the halftone mask 20 can be formed into a smooth shape corresponding to the light transmittance in the halftone mask 20 (that is, in the corresponding individual pixels). The amount of incident light can be increased), and the adhesion is good and no peeling occurs.

  However, when the ratio (I / M) is 20% or less, the adhesiveness is lowered and peeling occurs, and when the ratio (I / M) is 40% or more, the negative type formed by the negative type green film. The outer surface obtained by developing after pattern exposure in the color resist layer 18 through the halftone mask 20 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and the light on the outer surface is obtained. Scattering increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  The total amount (IM amount) of the initiator (I) and the monomer (M) with respect to the total resin amount (SP) of the initiator (I), the monomer (M) and the polymer (P) is 4% to 6%. If it is within the range, the outer surface obtained by developing after pattern exposure through the halftone mask 20 in the negative color resist layer 18 formed of the negative green film corresponds to the light transmittance in the halftone mask 20. The smooth shape can be obtained (that is, the amount of light incident on the corresponding individual pixel can be increased), and the adhesiveness is good and peeling does not occur.

  However, when the total amount (IM amount) is 4% or less, the adhesiveness is lowered and peeling occurs, and when the total amount (IM amount) is 6% or more, a negative type formed by a negative green film. The outer surface of the color resist layer 18 that has been subjected to pattern exposure through the halftone mask 20 cannot be made into a smooth shape corresponding to the light transmittance of the halftone mask 20, and light scattering on the outer surface is increased. . That is, the amount of light incident on the corresponding individual pixel is reduced.

  When at least one of the monomer type and the polymer type is not a single composition, the negative color resist layer 18 formed of the negative green film was developed after pattern exposure through the halftone mask 20 The outer surface cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and light scattering on the outer surface increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  -In addition to the trifunctional acrylic monomer as the monomer (M), if, for example, a 4 or 5 functional monomer used for a general resist is used, the photosensitivity becomes too high and the negative green film is formed. The outer surface obtained by developing after pattern exposure through the halftone mask 20 in the negative color resist layer 18 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and the outer surface. Scattering of light increases at. That is, the amount of light incident on the corresponding individual pixel is reduced.

  In addition, if the acid value of the polymer is in the range of 60 to 100, the negative color resist layer 18 formed of a negative green film is exposed after development through a halftone mask 20 after pattern exposure. The surface can have a smooth desired shape corresponding to the light transmittance in the halftone mask 20 (that is, the amount of light incident on the corresponding individual pixel can be increased).

  However, when the number is 100 or more, the developing speed becomes too fast, and the outer surface of the negative color resist layer 18 formed of the negative green film pattern-exposed through the halftone mask 20 is developed in the halftone mask 20 by development. The halftone mask 20 is not formed in the negative color resist layer 18 formed of the negative green film because the development rate becomes slow and the surface becomes rough when it becomes 60 or less, and the desired shape corresponding to the light transmittance cannot be obtained. The outer surface exposed through patterning cannot be made into a smooth shape corresponding to the light transmittance of the halftone mask 20 by development, and the scattering of light on the outer surface increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  In addition, when the average molecular weight of the polymer is in the range of 10,000 to 50,000, coating unevenness does not occur when the negative color resist layer 18 is formed and the pattern resolution of the resist is not deteriorated.

  However, when the average molecular weight is 10,000 or less, coating unevenness such as striation (straight coating unevenness) occurs, and when it is 50,000 or more, the resolution is deteriorated.

  Further, if the concentration (Pcon) of the green pigment in the green filter segment is in the range of 20 to 55% by weight, a predetermined green light spectrum can be obtained, and the negative type formed by a negative type green film. The outer surface obtained by developing after pattern exposure in the color resist layer 18 through the halftone mask 20 can be formed into a smooth shape corresponding to the light transmittance in the halftone mask 20 (that is, corresponding individual pixels). The amount of light incident on can be increased.

  However, if it is out of the range of 20 to 55% by weight, a predetermined green light spectrum cannot be obtained, and if it exceeds 55% by weight, half of the negative color resist layer 18 formed of the negative green film is formed. The outer surface obtained by developing after pattern exposure through the tone mask 20 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and light scattering on the outer surface increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  -And as a green pigment, C.I. I. Pigment green 36, C.I. I. Pigment Green 7 and C.I. I. A negative green film for a green filter having a thickness of 0.9 μm, prepared according to the method for producing a color filter shown in FIGS. 1 to 4 using the negative photosensitive green composition of Example 9 described above containing Pigment Yellow 139. The relationship between the wavelength of light and the transmittance in the green filter segment comprising C.I. I. Pigment green 36 and C.I. I. For a green filter having a film thickness of 0.9 μm prepared according to the method for producing a color filter described above with reference to FIGS. 1 to 4 using the negative photosensitive green composition of Example 9 described above containing Pigment Yellow 150 The relationship between the wavelength of light and the transmittance in a green filter segment made of a negative green film is shown by a thick solid line and a thin solid line in FIG.

  As shown in FIG. 8, the green filter segment according to the example has a substantially convex spectral transmittance curve in the visible light wavelength region (400 nm to 700 nm).

The transmittance of light having a wavelength between 400 nm and 435 nm and between 620 nm and 660 nm is 10% or less,
Between 480 nm and 515 nm and between 560 nm and 600 nm with a wavelength at which the light transmission is 50%, and
The transmittance of light having a wavelength of 530 nm is 70% or more.

  From these graphs, it can be seen that the green light has a high transmittance in the wavelength region and a low transmittance in the other wavelength regions, so that the green light is excellent in separability.

  In the case of such spectral transmittance characteristics, the transmittance is high in the green wavelength range (470 nm to 600 nm), and the transmittance is low in the wavelength range of other colors. An image with little is obtained.

[Formation of blue filter segment]
Next to the formation of the green filter segment described above, a case where a blue filter segment is formed on a predetermined corresponding photoelectric conversion element 12 will be described.

  In the above case, a negative type blue film formed of a negative type photosensitive blue composition as shown in FIG. 2 is further provided on the surface of the image sensor 14 on which a plurality of green filter segments are formed. The color resist layer 18 is configured, and the thickness RH of the negative color resist layer 18 in this case is also set in the range of 0.5 μm to 2.5 μm.

  The negative photosensitive green composition is a negative photosensitive blue composition in which at least a solvent, a blue pigment, a monomer, a polymer, an initiator, and an additive are mixed, and includes an initiator (I ) Ratio (I / M) is in the range of 20% to 40%, and the initiator (I) and the monomer with respect to the total resin amount (SP) of the initiator (I), the monomer (M) and the polymer (P) The total amount with (M) ranges from 6% to 7%, and the monomer species is a single composition and the polymer species is also a single composition.

  The monomer (M) is a trifunctional acrylic monomer. The polymer has an acid value in the range of 60-100 and an average molecular weight of 10,000-50,000.

  The blue pigment is C.I. I. Pigment blue 15: 6 and C.I. I. Pigment Violet 23 is included.

  The concentration of the blue pigment in the blue filter segment is adjusted to be in the range of 15 to 45% by weight.

  As the solvent, monomer, polymer, and initiator, the same ones as those used in the negative photosensitive green composition described above can be used.

  The surface of the negative color resist layer 18 formed of the negative blue film is formed by using a halftone mask 20 with a plurality of portions corresponding to the plurality of photoelectric conversion elements 12 to be formed corresponding to the blue filter segments. Pattern exposure 22 is performed. The halftone mask 20 has a hemispherical shape in which each of a plurality of portions of the green negative color resist layer 18 subjected to pattern exposure by the halftone mask 20 has a convex shape around the center of the corresponding photoelectric conversion element 12 after development. The gradation of the pattern is as follows.

  The halftone mask 20 used may be the same as that shown in FIG. 3 used for forming the green filter segment described above, and the negative color resist layer 18 formed of a negative blue film. The pattern exposure method using the halftone mask 20 may be the same as the pattern exposure method using the halftone mask 20 for the negative color resist layer 18 formed of the negative green film described above.

  After the pattern exposure, when the negative color resist layer 18 is developed, a plurality of exposed portions in the negative color resist layer 18, that is, on the side opposite to the plurality of photoelectric conversion elements 12 to be formed with corresponding blue filter segments. As shown in FIG. 4, only a plurality of positioned portions are blue filter segments having a convex hemispherical outer surface 24 a centered on the center of the corresponding photoelectric conversion element 12 at the top. It remains as 24.

  At this time, in this embodiment, the side surface 24b rising substantially vertically from the ultraviolet absorbing layer 16 in the filter segment 24 has a height BH of approximately 0.7 μm from the ultraviolet absorbing layer 16 to the edge opposite to the ultraviolet absorbing layer 16. Moreover, the convex hemispherical outer surface 24a on the upper part of the filter segment 24 has a height PH of approximately 0.5 μm from the edge to the apex of the side surface 24b. The dimensions of the heights BH and PH in the blue filter segment 24 are the same as the dimensions of the heights BH and PH in the green filter segment 24 described above.

  Finally, the blue filter segment 24 thus formed is hardened.

The inventor of the present application: variously changed the ratio (I / M) of the initiator (I) to the monomer (M) within a range of 20% to 40%, and the initiator (I) and the monomer (M) The total amount (IM amount) of the initiator (I) and the monomer (M) with respect to the total resin amount (SP) with the polymer (P) is variously changed within a range of 6% to 7%, and further the blue filter segment 8 types (Examples 1 to 8) of negative photosensitive blue compositions having the same composition were prepared except that the concentration (Pcon) of the blue pigment was varied in the range of 15 to 45% by weight. 8 types (Examples 1 to 8) of blue (Examples 1 to 8) prepared according to the method for producing a color filter described above with reference to FIGS. For each filter segment, cross-sectional shape, surface roughness, Image quality, adhesion, and residue are evaluated; at least one of the ratio (I / M), the total amount (IM amount), and the density (Pcon) is within the above range. 13 types (Comparative Examples 1 to 13) of negative photosensitive blue compositions having the same composition were prepared except for deviating from the above or using 2 polymer types. The cross-sectional shape, surface roughness, and the like for each of 13 types (comparative examples 1 to 13) of blue filter segments prepared according to the color filter manufacturing method described above with reference to FIGS. Evaluation was made on resolution, adhesion, and residue. The results are summarized in Table 3 below.

  Here, the cross-sectional shape was judged using an AFM (atomic force microscope). In other words, the curved shapes of the cross-section perpendicular to the two sides passing through the center of the green filter segment 24 having a substantially square shape and opposite to each other and the cross-section along the diagonal line are the light to be obtained from the used halftone mask. Judgment was made based on the separation from the ideal curved shape for condensing light. FIGS. 5A and 5B show examples of cases where these cross-sectional shapes are allowed close to the desired curve shape (OK) and cases where the cross-sectional shape is not allowed to deviate from the desired curve shape (NG). Has been.

  The surface roughness was measured using an SEM (operational electron microscope) and judged by comparison with a predetermined limit sample. FIGS. 6A, 6B, and 6C each show an example (NG) that is outside the allowable range, a limit sample, and an example that is within the allowable range (OK).

  The resist pattern resolution (determining whether the pattern dimensions obtained by pattern exposure and development are the desired dimensions) uses a side length SEM (side length / operation type electron microscope). And measured. The judgment criterion was “◯” if the pattern size was in the range of 2 μm ± 0.1 μm, and “△” or “x” if the pattern dimension was off.

Further, the adhesion was confirmed using a microscope, and the criterion was whether or not peeling occurred when exposure and development was performed with a certain amount of light or more. In addition to Table 3, the determination of exposure amount and adhesiveness was added in Table 4 below.

  Moreover, the residue was observed using a side length SEM (side length / operation type electron microscope), and judged by comparison with a predetermined limit sample. FIGS. 7A, 7B, and 7C show an example of a non-permissible range (NG), an example of a permissible range (OK), and a limit sample, respectively.

  In any case, if these cross-sectional shapes, surface roughness, resolution, adhesion, and residue are not within the criteria and tolerances as described above, the blue filter segment as described above will exhibit practically desired performance. I know I can't.

  That is, if the cross-sectional shape is poor, the desired curvature cannot be obtained and the light collecting property is deteriorated. If the surface roughness is rough, light is scattered on the lens surface, which causes color mixing and noise due to the scattered light. If the resolution is poor, a fine pattern cannot be obtained, and if there is a large amount of residue remaining in the unexposed area after development, color mixing and noise are caused.

  And the following were found in the process of analyzing Table 3 and in the process of creating Examples 1-8 and Comparative Examples 1-13 and evaluating performance.

  If the ratio (I / M) of the initiator (I) to the monomer (M) in the negative photosensitive blue composition is 20% to 40%, the negative color resist layer formed by the negative blue film 18, the outer surface obtained by developing after pattern exposure through the halftone mask 20 can have a smooth shape corresponding to the light transmittance in the halftone mask 20 (that is, incident on the corresponding individual pixels). The amount of light to be increased can be increased), and the adhesiveness is good and peeling does not occur.

  However, when the ratio (I / M) is 20% or less, the adhesiveness is lowered and peeling occurs, and when the ratio (I / M) is 40% or more, the negative type formed by a negative blue film. The outer surface obtained by developing after pattern exposure in the color resist layer 18 through the halftone mask 20 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and the light on the outer surface is obtained. Scattering increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  -The total amount (IM amount) of the initiator (I) and the monomer (M) with respect to the total resin amount (SP) of the initiator (I), the monomer (M) and the polymer (P) is 6% to 7%. If it is within the range, the outer surface obtained by pattern exposure through the halftone mask 20 in the negative color resist layer 18 formed of a negative blue film corresponds to the light transmittance in the halftone mask 20. The smooth shape can be obtained (that is, the amount of light incident on the corresponding individual pixel can be increased), and the adhesiveness is good and peeling does not occur.

  However, if the total amount (IM amount) is 6% or less, the adhesiveness is reduced and peeling occurs, and if the total amount (IM amount) is 7% or more, the negative type formed by a negative blue film. The outer surface obtained by developing after pattern exposure in the color resist layer 18 through the halftone mask 20 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and the light on the outer surface is obtained. Scattering increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  When at least one of the monomer type and the polymer type is not a single composition, the negative color resist layer 18 formed of the negative blue film was developed after pattern exposure through the halftone mask 20 The outer surface cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and light scattering on the outer surface increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  In addition to the trifunctional acrylic monomer as the monomer (M), for example, when a tetra- or pentafunctional monomer used for a general resist is used, the photosensitivity becomes too high and the negative blue film is formed. The outer surface obtained by developing after pattern exposure through the halftone mask 20 in the negative color resist layer 18 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and the outer surface. Scattering of light increases at. That is, the amount of light incident on the corresponding individual pixel is reduced.

  If the acid value of the polymer is in the range of 60 to 100, the outer surface obtained by developing after pattern exposure through the halftone mask 20 in the negative color resist layer 18 formed of a negative blue film Can be formed into a smooth desired shape corresponding to the light transmittance in the halftone mask 20 (that is, the amount of light incident on the corresponding individual pixel can be increased).

  However, when the number is 100 or more, the developing speed becomes too fast, and the outer surface developed after pattern exposure through the halftone mask 20 in the negative color resist layer 18 formed of the negative blue film is applied to the halftone mask 20. The halftone mask 20 is not formed in the negative color resist layer 18 formed of the negative blue film because the development rate is low and the surface becomes rough when the thickness is 60 or less. Thus, the outer surface obtained by developing after pattern exposure cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and the scattering of light on the outer surface increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  If the average molecular weight of the polymer is in the range of 10,000 to 50,000, coating unevenness does not occur when the negative color resist layer 18 is formed, and the resolution of the resist pattern is not deteriorated.

  However, when the average molecular weight is 10,000 or less, coating unevenness such as striation (straight-shaped coating unevenness) occurs, and when it is 50,000 or more, the resolution of the pattern is deteriorated.

  Further, if the concentration (Pcon) of the blue pigment in the blue filter segment is within the range of 15 to 45% by weight, a predetermined blue light spectrum can be obtained, and the negative type formed by the negative type blue film. The outer surface obtained by developing after pattern exposure in the color resist layer 18 through the halftone mask 20 can be formed into a smooth shape corresponding to the light transmittance in the halftone mask 20 (that is, corresponding individual pixels). The amount of light incident on can be increased.

  However, if it is out of the range of 15 to 45% by weight, a predetermined blue light spectrum cannot be obtained, and if it exceeds 45% by weight, half of the negative color resist layer 18 formed of a negative blue color film is formed. The outer surface obtained by developing after pattern exposure through the tone mask 20 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and light scattering on the outer surface increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  -And as a blue pigment, C.I. I. Pigment blue 15: 6 and C.I. I. Blue having a film thickness of 0.8 μm prepared according to the method for producing a color filter shown in FIGS. 1 to 4 using the negative photosensitive blue composition of Example 8 described above using the pigment violet 23 included. FIG. 9 shows the relationship between the wavelength of light and the transmittance in a blue filter segment composed of a negative blue film for a filter.

  As shown in FIG. 9, the blue filter segment according to the example has a substantially convex spectral transmittance curve in the wavelength region of visible light (400 nm to 700 nm).

The transmittance of light having a wavelength of 400 nm is 40% or more,
Having a wavelength between 480 nm and 520 nm with a light transmittance of 50%, and
The transmittance of light having a wavelength of 700 nm is 20% or less.

  From this graph, it can be seen that the transmittance of light in the blue wavelength region is high and the transmittance in other wavelength regions of light is low, so that the blue color separation is excellent.

  In the case of such spectral transmittance characteristics, the transmittance is high in the blue wavelength range (400 nm to 520 nm), and the transmittance is low in the wavelength range of other colors, so that the blue light extraction capability is excellent, and other colors are mixed. An image with little is obtained.

[Formation of red filter segment]
Following the formation of the green filter segment and the blue filter segment described above, a case where a red filter segment is finally formed on a predetermined corresponding photoelectric conversion element 12 will be described.

  In the above case, the negative type red film formed of the negative type photosensitive red composition as shown in FIG. 2 is further applied to the surface of the image sensor 14 on which the plurality of red filter segments are formed. The color resist layer 18 is configured, and the thickness RH of the negative color resist layer 18 in this case is also set in the range of 0.5 μm to 2.5 μm.

  The negative photosensitive red composition is a negative photosensitive red composition in which at least a solvent, a red pigment, a monomer, a polymer, an initiator, and an additive are mixed, and includes an initiator (I) for the monomer (M). ) Ratio (I / M) is in the range of 20% to 40%, and the initiator (I) and the monomer with respect to the total resin amount (SP) of the initiator (I), the monomer (M) and the polymer (P) The total amount of (M) ranges from 3.5% to 6%, and the monomer species has a single composition and the polymer species also has a single composition.

  The monomer (M) is a trifunctional acrylic monomer. The polymer has an acid value in the range of 60-100 and an average molecular weight of 10,000-50,000.

  The red pigment is C.I. I. Pigment red 177, C.I. I. Pigment red 48: 1, and C.I. I. Pigment Yellow 139 is included.

  The concentration of the red pigment in the red filter segment is adjusted to be in the range of 20 to 50% by weight.

  As the solvent, the monomer, the polymer, and the initiator, the same ones as those used in each of the negative photosensitive green composition and the negative photosensitive blue composition described above can be used.

  The surface of the negative color resist layer 18 formed of the negative red film is formed by using a halftone mask 20 with a plurality of portions corresponding to the plurality of photoelectric conversion elements 12 for which red filter segments are to be formed correspondingly. Pattern exposure 22 is performed. The halftone mask 20 has a convex hemispherical shape in which each of a plurality of portions of the red negative color resist layer 18 subjected to pattern exposure by the halftone mask 20 has a convex shape centering on the center of the corresponding photoelectric conversion element 12 after development. The gradation of the pattern is as follows.

  The halftone mask 20 to be used may be the same as that shown in FIG. 3 used for forming the green filter segment and the blue filter segment, and is a negative type formed of a negative type red film. The pattern exposure method using the halftone mask 20 for the color resist layer 18 also uses the halftone mask 20 for the negative color resist layer 18 formed of the negative green film and the negative blue film described above. The pattern exposure method may be the same.

  After the pattern exposure, when the negative color resist layer 18 is developed, a plurality of portions exposed in the negative color resist layer 18, that is, on the side opposite to the plurality of photoelectric conversion elements 12 to be formed with corresponding red filter segments. As shown in FIG. 4, only the plurality of positioned portions are red filter segments having a convex hemispherical outer surface 24 a centered on the center of the corresponding photoelectric conversion element 12 at the top. It remains as 24.

  At this time, in this embodiment, the side surface 24b rising substantially vertically from the ultraviolet absorbing layer 16 in the filter segment 24 has a height BH of approximately 0.7 μm from the ultraviolet absorbing layer 16 to the edge opposite to the ultraviolet absorbing layer 16. Moreover, the convex hemispherical outer surface 24a on the upper part of the filter segment 24 has a height PH of approximately 0.5 μm from the edge to the apex of the side surface 24b. The dimensions of the heights BH and PH in the red filter segment 24 are the same as the dimensions of the heights BH and PH in the green filter segment 24 and the blue filter segment 24 described above. .

  Finally, the red filter segment 24 thus formed is hardened.

The inventor of the present application: variously changed the ratio (I / M) of the initiator (I) to the monomer (M) within a range of 20% to 40%, and the initiator (I) and the monomer (M) The total amount (IM amount) of the initiator (I) and the monomer (M) with respect to the total resin amount (SP) with the polymer (P) is variously changed within a range of 3.5% to 6%, and further red Eight types (Examples 1 to 8) of negative photosensitive red compositions having the same composition were prepared except that the concentration (Pcon) of the red pigment in the filter segment was variously changed within the range of 20 to 50% by weight. 8 types (Examples 1 to 8) prepared according to the color filter manufacturing method described above with reference to FIGS. 1 to 4 using these 8 types (Examples 1 to 8) of the negative photosensitive red composition. Cross-sectional shape and surface roughness of each red filter segment , Resolution, adhesion, and residue evaluation; and at least one of the ratio (I / M), the total amount (IM amount), and the concentration (Pcon) Twelve types (Comparative Examples 1 to 12) of negative photosensitive red compositions having the same composition were prepared except for deviating from the range or using two polymer types, and these 12 types (Comparative Examples 1 to 12) of negatives. The cross-sectional shape and surface roughness of each of the 12 types (Comparative Examples 1 to 12) of red filter segments prepared according to the color filter manufacturing method described above with reference to FIGS. Evaluation was made on resolution, adhesion, and residue. The results are summarized in Table 5 below.

The cross-sectional shape, surface roughness, resolution, adhesion, and residue were evaluated in the same manner as in the green and blue cases described above. Further, the relationship between the exposure amount and the adhesion is added in Table 6.

  In any case, if the cross-sectional shape, surface roughness, resolution, adhesion, and residue are not within the criteria and tolerances as described above, the red filter segment as described above will exhibit practically desired performance. I know I can't.

  The following was found in the process of analyzing Table 5 and in the process of creating Examples 1 to 8 and Comparative Examples 1 to 12 and evaluating the performance.

  A negative color resist layer formed of a negative red film when the ratio (I / M) of the initiator (I) to the monomer (M) in the negative photosensitive red composition is 20% to 40%. 18, the outer surface obtained by developing after pattern exposure through the halftone mask 20 can have a smooth shape corresponding to the light transmittance in the halftone mask 20 (that is, incident on the corresponding individual pixels). The amount of light to be increased can be increased), and the adhesiveness is good and peeling does not occur.

  However, when the ratio (I / M) is 20% or less, the adhesiveness is reduced and peeling occurs, and when the ratio (I / M) is 40% or more, a negative type formed by a negative red film. The outer surface obtained by developing after pattern exposure in the color resist layer 18 through the halftone mask 20 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and the light on the outer surface is obtained. Scattering increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  -The total amount (IM amount) of the initiator (I) and the monomer (M) with respect to the total resin amount (SP) of the initiator (I), the monomer (M) and the polymer (P) is 3.5% to 6 % In the negative color resist layer 18 formed of a negative red film, the outer surface obtained by developing after pattern exposure through the halftone mask 20 is used as the light transmittance in the halftone mask 20. (I.e., the amount of light incident on the corresponding individual pixels can be increased), and the adhesiveness is good and peeling does not occur.

  However, when the total amount (IM amount) is 3.5% or less, adhesion is reduced and peeling occurs, and when the total amount (IM amount) is 6% or more, a negative red film is formed. The outer surface obtained by developing after pattern exposure through the halftone mask 20 in the negative color resist layer 18 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and the outer surface. Scattering of light increases at. That is, the amount of light incident on the corresponding individual pixel is reduced.

  When at least one of the monomer species and the polymer species is not a single composition, the negative color resist layer 18 formed of a negative red film was developed after pattern exposure through the halftone mask 20 The outer surface cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and light scattering on the outer surface increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  In addition to the trifunctional acrylic monomer as the monomer (M), for example, when a tetra- or pentafunctional monomer used for a general resist is used, the photosensitivity becomes too high and the negative red film is formed. The outer surface obtained by developing after pattern exposure through the halftone mask 20 in the negative color resist layer 18 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and the outer surface. Scattering of light increases at. That is, the amount of light incident on the corresponding individual pixel is reduced.

  If the acid value of the polymer is in the range of 60 to 100, the outer surface obtained by developing after pattern exposure through the halftone mask 20 in the negative color resist layer 18 formed of a negative red film Can be formed into a smooth desired shape corresponding to the light transmittance in the halftone mask 20 (that is, the amount of light incident on the corresponding individual pixel can be increased).

  However, when the number is 100 or more, the developing speed becomes too fast, and the outer surface of the negative color resist layer 18 formed of the negative red film is subjected to pattern exposure through the halftone mask 20 by development. The halftone mask 20 is not formed in the negative color resist layer 18 formed of the negative red film because the development rate is low and surface roughness occurs when the desired shape corresponding to the light transmittance cannot be obtained. Thus, the outer surface obtained by developing after pattern exposure cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and the scattering of light on the outer surface increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  In addition, when the average molecular weight of the polymer is in the range of 10,000 to 50,000, coating unevenness does not occur when the negative color resist layer 18 is formed, and pattern resolution is not deteriorated.

  However, when the average molecular weight is 10,000 or less, coating unevenness such as striation (straight coating unevenness) occurs, and when it is 50,000 or more, the resolution is deteriorated.

  Moreover, if the concentration (Pcon) of the red pigment in the red filter segment is in the range of 20 to 50% by weight, a predetermined red light spectrum can be obtained, and the negative type formed by the negative type red film. A smooth shape corresponding to the light transmittance in the halftone mask 20 can be obtained from the outer surface obtained by developing after pattern exposure in the color resist layer 18 through the halftone mask 20 (that is, corresponding individual pixels). The amount of light incident on can be increased.

  However, if it is out of the range of 20 to 50% by weight, a predetermined red light spectrum cannot be obtained, and if it exceeds 50% by weight, half of the negative color resist layer 18 formed of a negative red film is formed. The outer surface subjected to pattern exposure through the tone mask 20 cannot be made into a smooth shape corresponding to the light transmittance in the halftone mask 20, and light scattering on the outer surface increases. That is, the amount of light incident on the corresponding individual pixel is reduced.

  -And as red pigment, C.I. I. Pigment red 177, C.I. I. Pigment red 48: 1, and C.I. I. A film in the range of 0.5 to 2.5 μm prepared according to the method for producing a color filter shown in FIGS. 1 to 4 using the above-described representative negative photosensitive red composition of Example 8 containing Pigment Yellow 139. FIG. 10 shows the relationship between the wavelength of light and the transmittance in a red filter segment made of a negative red film for red filter having a thickness.

  As shown in FIG. 10, the red filter segment according to the example has a substantially S-shaped spectral transmittance curve in the wavelength range of visible light.

The transmittance of light having a wavelength of 400 nm is 20% or less,
The transmittance at a wavelength between 430 nm and 560 nm is 10% or less, and
Between 570 nm and 600 nm has a wavelength at which the light transmittance is 50%,
The transmittance of light having a wavelength of 600 nm is 75% or more.

  From this graph, it can be seen that the light transmittance in the red wavelength region is high and the transmittance in the other light wavelength regions is low, so that the red light separation property is excellent.

  In the case of such spectral transmittance characteristics, the transmittance is high in the red wavelength range (570 nm or more) and the transmittance is low in the wavelength range of other colors, so that the red light extraction capability is excellent, and the color mixture of other colors is improved. Less images can be obtained.

It is a schematic longitudinal cross-section of the conventional image pick-up element in which the several CMOS photoelectric conversion element is provided in the semiconductor substrate. On the semiconductor substrate of the image sensor of FIG. 1, any of an ultraviolet absorbing layer and a negative photosensitive green composition, a negative photosensitive blue composition, and a negative photosensitive red composition according to an embodiment of the present invention. A negative color resist layer is formed by any one of the negative green film for green filter, the negative blue film for blue filter, and the negative red film for red filter. It is a longitudinal cross-sectional view which shows a mode that exposure processing is performed using it. FIG. 3 is a schematic plan view of the halftone mask used in FIG. FIG. 4 shows a development process of the negative color resist layer after the exposure process in FIG. 2 and further a hardening process, so that any of a green filter segment, a blue filter segment, and a red filter segment having a desired cross-sectional shape is obtained. It is a longitudinal cross-sectional view which shows a mode that these 1 types were formed corresponding to the predetermined photoelectric conversion element on the semiconductor substrate of the image pick-up element of FIG. FIG. 5A shows a green filter segment, a blue filter segment, and a red filter segment having a substantially square shape in FIG. 4 formed in correspondence with a predetermined photoelectric conversion element on the semiconductor substrate of the image pickup element in FIG. The cross-sectional shape of any one of the filter segments is obtained from the ideal curves of the cross section orthogonal to the two sides opposite to each other through the center of the filter segment using an AFM (Atomic Force Microscope) and the cross section along the diagonal line. FIG. 5B is a cross-sectional shape similar to that of FIG. 5A, but is determined from the ideal curve. It is a figure which shows the case where it is judged that it is not accept | permitted (NG) by a separation condition. 6A shows a green filter segment, a blue filter segment, and a red filter segment having a substantially square shape in FIG. 4 formed in correspondence with a predetermined photoelectric conversion element on the semiconductor substrate of the imaging element in FIG. FIG. 7 is a perspective view showing a case where the surface roughness of any one of the filter segments is determined to be out of tolerance (NG) after being measured using an SEM (operational electron microscope); (B) is a perspective view similar to (A) of FIG. 6, but is a perspective view showing a case where the surface roughness is determined to be an allowable limit; and (C) of FIG. FIG. 7 is a perspective view similar to FIG. 6A, but showing a case where the surface roughness is determined to be within an allowable range (OK). FIG. 7A shows a green filter segment, a blue filter segment, and a red filter segment having a substantially square shape in FIG. 4 formed in correspondence with a predetermined photoelectric conversion element on the semiconductor substrate of the image pickup element in FIG. It is a top view which shows the case where it is judged that any one residue of a filter segment is outside tolerance (NG) after being observed using a side length SEM (side length / operation type electron microscope). FIG. 7 (B) is a plan view similar to FIG. 7 (A), but is a plan view showing a case where the residue is determined to be within an allowable range (OK); and FIG. (C) is a plan view similar to (A) of FIG. 7, but is a plan view showing a case where the residue is determined to be within the allowable range. FIG. 8 shows a negative green film for a green filter having a film thickness in the range of 0.5 to 2.5 μm prepared from a negative photosensitive green composition according to one embodiment of the present invention. 4 is a diagram showing the relationship between the wavelength of light and the transmittance in a red filter segment prepared according to the color filter manufacturing method described above with reference to 4 and having a green pigment concentration in the range of 20 to 55% by weight. FIG. 9 shows a negative blue film for a blue filter having a film thickness in the range of 0.5 to 2.5 μm prepared from a negative photosensitive blue composition according to an embodiment of the present invention. 4 is a diagram showing the relationship between the wavelength of light and the transmittance in a blue filter segment prepared in accordance with the method for producing a color filter described above with reference to 4 and having a blue pigment concentration in the range of 15 to 45% by weight. FIG. 10 shows a negative red film for a red filter having a film thickness in the range of 0.5 to 2.5 μm prepared from a negative photosensitive red composition according to an embodiment of the present invention. 4 is a diagram showing the relationship between the wavelength of light and the transmittance in a red filter segment having a red pigment concentration of 20 to 50% by weight prepared according to the color filter manufacturing method described above with reference to FIG. (A) is a longitudinal sectional view schematically showing a longitudinal section of an example of a conventional image sensor with a color filter; and (B) is a longitudinal section of another example of an image sensor with a conventional color filter. It is a longitudinal section showing roughly. It is a longitudinal cross-sectional view which shows schematically the longitudinal cross-section of another example of the conventional image pick-up element with a color filter.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Semiconductor substrate, 12 ... Photoelectric conversion element, 14 ... Image pick-up element, 16 ... Ultraviolet absorption layer, 18 ... Negative color resist layer, 20 ... Halftone mask, 24 ... Filter segment, 24a ... Outer surface, 24b ... Side surface.

Claims (26)

A negative photosensitive green composition in which at least a solvent, a green pigment, a monomer, a polymer, an initiator, and an additive are mixed,
The ratio of initiator (I) to monomer (M) (I / M) ranges from 20% to 40%;
The total amount of initiator (I) and monomer (M) relative to the total resin amount (SP) of initiator (I), monomer (M) and polymer (P) ranges from 4% to 6%; and ,
The monomer species is a single composition and the polymer species is a single composition.
A negative photosensitive green composition characterized by the above.   The negative photosensitive green composition according to claim 1, wherein the monomer (M) is a trifunctional acrylic monomer.   The negative photosensitive green composition according to claim 1, wherein the polymer has an acid value in the range of 60 to 100 and an average molecular weight of 10,000 to 50,000. As a green pigment, C.I. I. Pigment green 36, C.I. I. Pigment Green 7 and C.I. I. Pigment yellow 139, and
The concentration of the green pigment in the green filter is in the range of 20 to 55% by weight.
The negative photosensitive green composition according to claim 1. As a green pigment, C.I. I. Pigment green 36 and C.I. I. Pigment Yellow 150, and
The concentration of the green pigment in the green filter is in the range of 20 to 55% by weight.
The negative photosensitive green composition according to claim 1. A negative green film for a green filter having a film thickness in the range of 0.5 to 2.5 μm, having a substantially convex spectral transmittance curve in the wavelength region of visible light,
The transmittance of light having a wavelength between 400 nm and 435 nm and between 620 nm and 660 nm is 10% or less,
Between 480 nm and 515 nm and between 560 nm and 600 nm with a wavelength at which the light transmission is 50%, and
The transmittance of light having a wavelength of 530 nm is 70% or more.
A negative green film for a green filter characterized by the above. A negative green film for a green filter having a film thickness in the range of 0.5 to 2.5 μm, having a substantially convex spectral transmittance curve in the wavelength region of visible light,
The transmittance of light having a wavelength between 400 nm and 435 nm and between 620 nm and 660 nm is 10% or less,
Between 460 nm and 510 nm and between 550 nm and 600 nm having a wavelength at which the light transmission is 50%, and
The transmittance of light having a wavelength of 530 nm is 70% or more.
A negative green film for a green filter characterized by the above. A color filter comprising at least one green filter segment arranged corresponding to a plurality of photoelectric conversion elements of an image sensor,
The green filter segment is formed of the negative photosensitive green composition according to any one of claims 1 to 5, and
The green filter segment contains 20 to 55% by weight of a green pigment,
A color filter characterized by that.   The color filter according to claim 8, wherein a surface of the green filter segment located on the opposite side to the corresponding photoelectric conversion element is formed in a convex lens shape. A negative green film is formed from the negative photosensitive green composition according to any one of claims 1 to 5 corresponding to at least one of the plurality of photoelectric conversion elements of the imaging element,
Developing the negative green film after pattern exposure using a density distribution mask,
A green filter is formed in which the surface located on the side opposite to the corresponding photoelectric conversion element after development is formed in a convex lens shape,
A method for producing a color filter, comprising: A negative photosensitive blue composition in which at least a solvent, a blue pigment, a monomer, a polymer, an initiator, and an additive are mixed,
The ratio of initiator (I) to monomer (M) (I / M) ranges from 20% to 40%;
The total amount of initiator (I) and monomer (M) relative to the total resin amount (SP) of initiator (I), monomer (M) and polymer (P) ranges from 6% to 7%; and ,
The monomer species is a single composition and the polymer species is a single composition.
A negative photosensitive blue composition characterized by the above.   The negative photosensitive blue composition according to claim 11, wherein the monomer (M) is a trifunctional acrylic monomer.   The negative photosensitive blue composition according to claim 11, wherein the acid value of the polymer is in the range of 60 to 100 and the average molecular weight is 10,000 to 50,000. As a blue pigment, C.I. I. Pigment blue 15: 6 and C.I. I. Pigment violet 23, and
The concentration of the blue pigment in the blue filter is in the range of 15 to 45% by weight,
The negative photosensitive blue composition according to claim 11. A negative blue film for a blue filter having a film thickness in the range of 0.5 to 2.5 μm, having a substantially convex spectral transmittance curve in the wavelength region of visible light,
The transmittance of 400 nm wavelength light is 40% or more,
Having a wavelength between 480 nm and 520 nm with a light transmittance of 50%, and
The transmittance of 700 nm wavelength light is 20% or less,
A negative blue film for a blue filter characterized by the above. A color filter comprising at least one blue filter segment arranged corresponding to a plurality of photoelectric conversion elements of an imaging element,
The blue filter segment is formed of the negative photosensitive blue composition according to any one of claims 11 to 14, and
The blue filter segment contains 15 to 45% by weight of a blue pigment,
A color filter characterized by that.   The color filter according to claim 14, wherein a surface of the blue filter segment located on a side opposite to a corresponding photoelectric conversion element is formed in a convex lens shape. A negative blue film is formed from the negative photosensitive blue composition according to any one of claims 11 to 14 corresponding to at least one of the plurality of photoelectric conversion elements of the imaging element,
Developing the negative blue film after pattern exposure using a density distribution mask,
A blue filter is formed in which the surface located on the side opposite to the corresponding photoelectric conversion element after development is formed in a convex lens shape,
A method for producing a color filter, comprising: A negative photosensitive red composition in which at least a solvent, a red pigment, a monomer, a polymer, an initiator, and an additive are mixed,
The ratio of initiator (I) to monomer (M) (I / M) ranges from 20% to 40%;
The total amount of initiator (I) and monomer (M) relative to the total resin amount (SP) of initiator (I), monomer (M) and polymer (P) is in the range of 3.5% to 6%. And
The monomer species is a single composition and the polymer species is a single composition.
Negative photosensitive red composition characterized by the above.   The negative photosensitive red composition according to claim 19, wherein the monomer (M) is a trifunctional acrylic monomer.   20. The negative photosensitive red composition according to claim 19, wherein the acid value of the polymer is in the range of 60 to 100 and the average molecular weight is 10,000 to 50,000. As a red pigment, C.I. I. Pigment red 177, C.I. I. Pigment red 48: 1, and C.I. I. Pigment yellow 139, and
The concentration of the red pigment in the red filter is in the range of 20-50% by weight,
The negative photosensitive red composition according to claim 19. A negative red film for a red filter having a thickness in the range of 0.5 to 2.5 μm, having a substantially S-shaped spectral transmittance curve in the wavelength region of visible light,
The transmittance of 400 nm wavelength light is 20% or less,
The transmittance of light having a wavelength between 430 nm and 560 nm is 10% or less,
Having a wavelength between 570 nm and 600 nm with a light transmission of 50%, and
The transmittance of light having a wavelength of 600 nm is 75% or more.
Negative type red membrane for red filter characterized by the above. A color filter comprising at least one red filter segment arranged corresponding to a plurality of photoelectric conversion elements of an imaging element,
The red filter segment is formed of the negative photosensitive red composition according to any one of claims 1 to 4, and
The red filter segment contains 20 to 50% by weight of a red pigment,
A color filter characterized by that.   25. The color filter according to claim 24, wherein a surface of the red filter segment located on a side opposite to the corresponding photoelectric conversion element is formed in a convex lens shape. A negative red film is formed from the negative photosensitive red composition according to any one of claims 19 to 22, corresponding to at least one of the plurality of photoelectric conversion elements of the imaging element,
Developing the negative red film after pattern exposure using a density distribution mask,
A red filter is formed in which the surface located on the side opposite to the corresponding photoelectric conversion element after development is formed in a convex lens shape,
A method for producing a color filter, comprising:

Images